1. Field of the Invention
The present invention relates to a semiconductor probe having a wedge shape resistive tip and a method of fabricating the same and, more particularly, to a semiconductor probe having a wedge shape resistive tip in which electrodes are formed on both sides of the resistive tip, and a method of fabricating the same.
2. Description of the Related Art
With the increase in demand for small electronic devices such as mobile communication terminals and personal digital assistants comes the need for ultra small highly integrated recording media. However, since miniaturization of the conventional hard disk is not easy, and high integration of flash memory is also difficult, research is also conducted on information storage devices using a scanning probe.
A scanning probe is used for various scanning probe microscopic (SPM) techniques. Examples of these are a scanning tunneling microscope (STM), that reads information by detecting a current that flows according to a voltage difference applied between a scanning probe and a specimen, an atomic force microscope (AFM), that uses an atomic force between a scanning probe and a specimen, a magnetic force microscope (MFM) that uses a magnetic force between a magnetic field of a specimen and a magnetized scanning probe, a scanning near-field optical microscope (SNOM) that overcomes the resolution limits of visible light, and an electrostatic force microscope (EFM) that uses electrostatic charge between a specimen and a scanning probe.
In order to read and write information at high speed and high density using the SPM techniques, the scanning probe must be able to detect the surface charge of regions as small as a few tens of nanometers in diameter. Also, in order to increase the read and write speed, cantilevers must be fabricated in an array.
FIG. 1 is a cross-sectional view of a cantilever 70 having a resistive tip 50 disclosed in International Patent Publication No. WO 03/096409. The resistive tip 50 is formed vertically on the cantilever 70, can be fabricated in an array, and can have a resistance region 56 with a diameter of a few tens of nanometers.
Referring to FIG. 1, the resistive tip 50 of a semiconductor probe includes a main body 58 doped with a first impurity, the resistance region 56 that is located on an end portion of the resistive tip 50 and is doped with a low concentration of a second impurity, and first and second semiconductor electrode regions 52 and 54 which are located on both side slopes of the main body 58 and are doped with a high concentration of the second impurity.
However, in the semiconductor probe having the conventional resistive tip 50, the regions of the slopes of the first and second semiconductor electrode regions 52 and 54 doped with a high concentration are reduced by excessive etching during a wet etching process for forming the resistive tip 50. Accordingly, the conductive regions on the slopes are reduced, which increases the resistance region 56, thereby reducing the spatial resolution of resistance variation.